Convert string to ASCII value python：http://stackoverflow.com/questions/8452961/convert-string-to-ascii-value-python

https://docs.python.org/2/library/string.html

http://www.pythoncentral.io/python-unicode-encode-decode-strings-python-2x/

https://www.daniweb.com/software-development/python/threads/295920/convert-string-to-ascii-then-to-list

http://code.activestate.com/recipes/65117-converting-between-ascii-numbers-and-characters/

python中将string转码为ASCII格式